scheduler: Schedule tasks

In Spiritspeak/often: Schedules functions to run at periodic intervals

Description

The following functions allow users to schedule functions in a virtual agenda, and initiate a loop that periodically checks whether any particular function is due.

Usage

tableEnv()

addJob(code, runtime, loopid = "main")

delJob(jobid, jobnum, status, delete = TRUE)

jobList()

setLoop(
  loopid = "main",
  rate = 1,
  tolerance = 60,
  on.error = "continue",
  on.miss = "continue",
  on.complete = "terminate"
)

startLoop(loopid = "main")

stopLoop(loopid = "main")

Arguments

code	Code of any length. It will remain unevaluated until the job is run - save for the parts of the code wrapped in .() brackets.
runtime	a future timestamp (use in conjunction with now() for convenience)
loopid	A handle to an event loop.
jobid	one or multiple jobids, which serve as identifiers for the scheduled jobs, to be deleted
jobnum	Number of job(s) to be deleted
status	status of job(s) to be deleted
delete	Logical. If true, deletes jobs from schedule. If false, sets their status to 'disabled' instead. Default is TRUE.
rate	numeric, in seconds. How often should the loop check for a new task to be run?
tolerance	numeric, in seconds; jobs that were scheduled this many seconds in the past will still be run. Jobs beyond this point will be considered missed.
on.error	character; what is to be done when a job results in an error? Defaults to "continue".
on.miss	character; what is to be done when a job is missed? Defaults to "continue".
on.complete	character; what is to be done to the loop when there are no more jobs to be run? Defaults to "terminate".

Details

A job can be any line(s) of code, and it will be run at the designated timstamp if the associated loop is running.

startLoop() starts a loop.

stopLoop() stops a loop.

Value

delJob() returns TRUE if successful, FALSE if failed.

Functions

• tableEnv: Returns the environment containing the looptable and the jobtable, allowing for direct modification rather than through helper functions.

• addJob: Add a job to the schedule.

• delJob: Delete a job. Use in conjunction with jobList(). Deletes job(s) based on their number in the job queue/schedule, their IDs, or their status.

• jobList: Returns a data.frame containing all jobs, finished and unfinished.

• setLoop: Configure an existing loop or create a new loop with custom settings. When started using startLoop(), this loop will periodically check for jobs to execute. When an unknown loopid is given, a new loop is created.

• startLoop: Start a loop with given loopid.

• stopLoop: Stop a running loop.

Examples

addJob(code=print("Hello World"),runtime=now()+5)
delme<-addJob(code=print("Goodbye World"),runtime=now()+6)
delJob(jobid=delme)
addJob(code=stopLoop(),runtime=now()+7)
setLoop(rate=0.5)
print(jobList())
startLoop()

Spiritspeak/often documentation built on Feb. 2, 2021, 11:41 a.m.